diff -up src/sage/modular/arithgroup/farey.cpp.orig src/sage/modular/arithgroup/farey.cpp --- src/sage/modular/arithgroup/farey.cpp.orig 2015-10-11 17:20:15.809728677 -0300 +++ src/sage/modular/arithgroup/farey.cpp 2015-10-11 17:20:28.178729151 -0300 @@ -136,6 +136,7 @@ operator*(const SL2Z& M, const vector